Distributed systems -- All the problems and opportunities of concurrent systems, but more so.

Type systems -- We're still just scratching the surface of how compilers can help us make maintainable systems. Halide is a pretty interesting example of better human/compiler communication.

Privacy -- this page, for instance, does not track you, and is served over HTTPS so your ISP can't inject
JavaScript into it.

You can contact me on Twitter or via email at (my first name @ this domain).

Open source

A few of my open source projects:

The Rust version of HdrHistogram. All too often, systems are
measured via numbers with little practical utility like "mean
latency". HdrHistogram is a useful data structure for building tools that banish
such pseudo-metrics from your systems. It has a small, constant memory footprint with very fast updates.

Rust Base64. The de-facto base64 implementation for the
Rust community, and an opportunity to practice low level optimization. Do you need multiple GiB/s of
base64? Maybe not today...

Rust implementation of StreamVByte. StreamVByte is an approach to integer compression that is
SIMD-friendly with a C reference implementation. The Rust implementation is a way to explore Rust's SIMD support
as well as the ability to expose zero-cost abstractions. And, of course, if you need to read or write billions
of ints per second, it can do that too.